My Slutty Ex-Gf

I need to get this story off my chest. It lives rent free in my head, haunting me, like the spectre of an ex-girlfriend past that just won't let me move on.

Her name was Cassie, and she went to my high school. Cassie was one of those really hot girls who wasn't part of the pretentious, popular crowd. She was bubbly and sweet, so kind and yet flirty with everyone. She had a big, genuine smile, beautiful hair that smelled so nice, and a rail thin physique with curves in all the right places. Imagine the bombshell nerd girl back at your high school. Yeah, that was Cassie. She was real down to earth, and as a result, all the guys she hung out with had a crush on her. She also had a reputation for sucking dick. Any guy she went on a date with was likely to get his dick sucked, regardless of how much she ended up liking him. It was like a rite of passage for guys in my class. Go on a date with Cassie, get your dick sucked. And the rumor was, she was damn good at it and always swallowed.

I was lucky enough to date Cassie at the end of my senior year. I got the blow job treatment - just as good as advertised - and so much more. The summer after we graduated, we lost our virginity to each other. It was incredible. From that moment on, we were inseparable and had sex every chance we'd get.

I now have to tell you about my little brother, Derek. Derek is two years younger than me and has Down's Syndrome. He's lucky, he doesn't really have that Down's Syndrome look, just a bit short and stocky, and his face is actually kind of handsome. Derek has limited intellect and doesn't speak much, but he's a really sweet kid. Well, let me tell you, when I started dating Cassie and brought her to meet the family, Derek was obsessed. It was obvious from the start he had a crush on her - I mean, who wouldn't? But it was funny how much she made him stammer, and how much he'd blush whenever she looked at him. Not only that, he'd always get a boner - a really big boner - and never had the awareness to try to hide it. We'd all be hanging out, Cassie would give a compliment to Derek, and his dick would get big and hard in his sweatpants. It was absurd.

Cassie was a great sport about it and really understanding. Moreover, I think she was flattered and amused. I noticed her do things on purpose to evoke him, hugging him close so he'd feel her tits, winking at him, and complimenting him any chance she got. I even caught her brushing against it once or twice, like she was copping a feel. She was a total cock tease, and Derek ate that shit right up.

Cassie and I ended up dating a couple of years. We went to college in our hometown, and my parents would pay for things we did as long as we brought Derek along. We loved Derek dearly, so we took him almost everywhere - to the beach, to the movies, to amusement parks - though Cassie and I made plenty of time alone for sex.

One day, when Derek's 18th birthday was approaching, Cassie mentioned wanting to do something special for him. I said sure, of course, why not? She mentioned that he seemed really lonely and was way too shy to date, even with girls at the youth center who shared his disability. She said she wanted to teach him about safe sex and even give him a handjob. I couldn't believe my ears.

"You want to jack off my disabled little brother?" I asked.

"You don't have to say it like that," she said. "What's the big deal, he jacks himself off all the time? This would just be to give him a little confidence, maybe he won't be so shy around girls?"

I felt it was super weird, but she kept assuring me it was no big deal. Besides, people with Down's Syndrome are often overlooked in the sex ed department, and she wanted to teach him about proper condom use.

I finally agreed after she made me feel like an asshole for refusing. We had plans to watch his favorite movie, Dumb and Dumber, in the basement on his birthday, so she decided she'd make at pass at him on the couch. Well, it went just as expected. In the scene where Lloyd lifts Mary's skirt to flash her ass to the camera, Derek popped a boner right on cue.

Cassie, sitting between us in a t-shirt and mini skirt, squeezed my hand and then glanced at his erection. She had a huge smile on her face which I'll never forget. I rolled my eyes and then nodded my approval.

"Oh, Derek," she said in a sing-song tone. She put her hand on his thigh, right next to his massive bulge. Enraptured by the film, he hardly seemed to notice. "Hey, Derek, let me help you with that." She grabbed his cock through his sweatpants, and she immediately had his attention. She started stroking him lightly, while her stared dumbfounded at her hand on his dick. "Do you like that, Derek? Does that feel good?"

Derek nodded, staring down with his jaw hanging open.

"This is called a handjob," Cassie said. "Girls can do this for boys when they really like them. Is it okay if I keep going?"

"Y- yes," he said.

"You're a really nice boy, Derek," Cassie said. "I bet if you talked to more girls at the center, some of them would want to do this for you." He continued to stare at her stroking hand, transfixed. I couldn't decide if this was cringey or arousing, but the word "slut" kept echoing in my head. "Is it okay if I take it out of your pants, Derek?" she asked.

"Y- yes," he said.

She slowly lowered his pants, revealing a long, fat erection. It was at least 8 inches, a few good inches longer than mine, and almost twice as fat.

"My," Cassie said. "You're a big boy, Derek." She grabbed his meat and kept on stroking, gradually and gently, as if in slow motion.

"Unh," Derek groaned with delight.

Cassie stole a quick look at me. Her eyes and smile were lit up like a Christmas tree. *It's so big*, she mouthed to me wordlessly, then she turned back to Derek. I swallowed hard, feeling my face turn red. My own more modest erection had started to build, and I was trying to hide it in my shame. But I'm certain Cassie didn't notice.

A drop of precum had formed at the head of Derek's penis. Cassie wiped it off with her index finger and stuck it in her mouth. "Mmm," she said. "You taste just as sweet as you look, Derek!"

My stomach lurched with revulsion, but my cock also twitched in my jeans. "Cassie," I hissed, what are you doing?"

Ignoring me, she spit on her hand and started rubbing it on Derek's hard dick. The bulbous head was starting to glisten. Time after time, she spit in her palm and then rubbed it on his penis until it was good and moist. "Now how does that feel?" she asked.

"Good," Derek said.

Without looking away from Derek's penis, Cassie found my hand and moved it up under her tiny skirt. Even through her cotton panties, I could tell she was soaking wet! I couldn't believe my own brother was turning her on this much. She'd never forgive me if I called a stop to this now. There was nothing for me to do but roll with it and start fingering her.

Then she pulled out a magnum condom out of her purse. The wrapper was big and gold and shiny, I'd never seen one before now. "Derek, this is a condom," Cassie said. "You use this when you have sex with women. I'll show you how to put it on. Use it every time, okay?"

"Okay," Derek said.

She opened the wrapper and removed the slimy, pre-lubed rubber with her fingertips. "It goes on just like this," she said. She held it to the tip of his penis and then rolled it on down the length of his shaft, almost to his balls. "Now I'll show you what a blowjob is."

"What?!" I almost sputtered. But Cassie ignores me. She repositions herself to a kneeling position on the couch, her cute little ass lifted right in my face.

"Girls will do this for you if they really like you, Derek," she said. "And I really like you." And with that, she put her mouth over his condom covered shaft and started sucking.

I was utterly shocked. We hadn't discussed things going this far. I now could smell the cream of her vagina, her little ass and pussy pushed right up in my face. Not wanting to be left out, I continued touching her over her little white thong panties, nuzzling her slit with my nose and kissing her ass and her inner thighs. Then I pulled her panties aside to lick her proper.

Derek was moaning wildly now. I figured he had to be close to the finish. I took peeks when I could, trying to see how deep she was taking him. She got a bit more than halfway before gagging, but she was doing her best. She'd never struggled so much with me.

She next lifted her head and said, "You're such a good boy, Derek. And I really want you to have a good birthday. Do you mind if I - sit on it a little?"

I had to object. "What the fuck, Cassie? You're trying to fuck my brother? This has gone too far."

"Relax, Jack," she answered. "I'm just so curious, his dick is so big, I want to see how it feels. Besides, he's wearing a condom, so it's not that big a deal."

"Not that big a deal? Are you kidding me?"

"Listen," she said, "just let me try it for a minute, I'm sure he won't last long. I want to feel stretched for once, and I'll probably never have a chance again. You can fuck my face while I ride him. And if you let me do this, then later - I'll let you fuck my ass."

She gazed up into my eyes and fluttered her lashes, looking innocent and earnest. I couldn't believe it, but it was hard to say no to that desperate, pleading face. Plus, I'd been wanting to fuck her ass for ages, and I finally had my chance. "I can't believe I'm saying this," I say, "but fine."

Derek, staring silently in wonder, watched as Cassie stood up and dropped her panties. Still wearing her skirt, she stood in front of him and positioned her pussy over his hulking dick. I watched in horror as she lowered herself down, his massive head stretching her tiny pussy. Wet as it was, it was a struggle to fit it inside. From experience, I know that Cassie is exceptionally tight. She spread her ass and pussy just to get it in, and finally, it pushed most of the way inside.

"Oh my God, that's so big," she cooed. "I'm going to move slow, Derek. Hold back your cum, I want this to last."

She started riding up and down, slowly and carefully, occasionally whimpering now and again. I stood in front of her and dropped my pants, and she faithfully started sucking my dick. Unlike with Derek, she could deep throat me easily, and it felt so good. I could even fuck her throat without her gagging, and I did so while she was riding up and down.

Soon she picked up the pace on his dick, cooing and squealing with delight. She made noises she'd never made for me, and I wondered if he was making her cum. Her skirt unfortunately blocked my view. Eventually, she paused and stood up, his condom-covered dick slipping out of her.

"Two orgasms," she said, "and counting. It's so intense, but you're doing great, Derek. I needed a break but - I want to make you cum. I'm going to go faster this time to help you finish. Are you ready?"

"Unh, I'm ready!" he said.

She lowered down, and this time rode him with force. I fucked her throat even faster now, matching their rhythm. It was so hot for some reason, thinking what a slut she was for fucking my brother, just because he has a big dick.

I think we all came at the same time, each moaning and groaning as our bodies pulsed with pleasure. I unloaded in Cassie's mouth, and she licked it clean and swallowed every drop. She was still sitting on Derek's cock when she looked over and noticed his discarded condom next to him on the couch.

"Um, Derek," she began. "Did you take the condom off?"

Derek started to giggle nervously.

"Derek, no!" she exclaimed, hopping off his raw, softening dick. His cum was dripping out of her. "Derek, that was really bad!"

Needless to say, I didn't date Cassie much longer. I did get my turn to cum in her ass - amazing, by the way - but I could never think of her the same after she'd fucked my brother. I kept tabs on her a bit after the breakup. She joined a sorority and became a mega slut, sleeping with half the neighboring fraternity by the time of graduation. I convinced her to tell me some stories from time to time, but those are for another day. Also, in an abundance of caution, I stopped letting Derek hang out with my girlfriends. Apparently, he's really popular now with the girls down at his day program. I can only wonder why.